1. Technical Field
The present invention is in the field of non-volatile programmable integrated circuits using standard CMOS technology.
2. Related Art
Floating gate reference circuits generate a reference voltage in response to the charge stored on the floating gate of a nonvolatile memory transistor. The nonvolatile memory transistor is typically programmed through the thin oxide of a programming capacitor. However, charge can leak through this thin oxide when bias voltage is applied over long periods of time, especially at high temperatures, thereby undesirably affecting the generated reference voltage. It would therefore be desirable to have a circuit for accurately programming a nonvolatile memory transistor in a floating gate reference circuit, and then maintaining the programmed charge over a long period of time.